Help with HC cuba not growing/ slow growth of plants in general.

[Fernystein]

Hi everyone, wanted to share my problem with you.
My tank has been neglected for a couple of months (during january-february), and I started having BBA problems on my hardscape and on a few spots of the HC carpet that I had.
I've since removed the parts that were infested with algae, and now I have to basically start over with the remaining cuba stems.
I never dosed fertilizers that much in the past years (tank is 3 years old), but I managed to grow a thick carpet by just soil, light and co2. Sadly the carpet is now gone, and plants are struggling...
After the bba disaster, I started dosing first tropica specialised nutrition, and now TNC complete, on a daily basis, following the EI calculator, but lowering the dose a bit, since I don't have that many plants.
Tried adding some root tabs, because I think that after all these years, the soil is now depleted.

The tank is 55 L (not counting soil and hardscape) and I am dosing 4,5 ml of TNC complete daily, with two 25% Water changes during the week.
Co2 Drop checker is green (I've re-adjusted the Co2 level more than a week ago, I was dosing too little before).
Light is Chihiros A451 PLUS. 7200 lumens, 35 watt, at 50% power 8 hours a day.
Temperature is a bit high, usually at 26-27 C through the day.

I think that the light is enough, fertilizers are abundant in the water column and the co2 is stable at green all day, but I don't see the explosive growth I saw when I started the tank three years ago, even the stem plants are not growing that fast as they used to. Am I dosing too much? Too little? Is light enough?

 

[_Maq_]

Water movement low, oxygen level low, overfertilization, too much organic matter/compounds => too many microbes => too high oxygen consumption.
This is a possible explanation. We'd have to have more pics, more details on your water.

 

[Fernystein]

Water movement low, oxygen level low, overfertilization, too much organic matter/compounds => too many microbes => too high oxygen consumption.
This is a possible explanation. We'd have to have more pics, more details on your water.

Wait, what does the high oxygen consumption do?
Anyway, as for the water, i measured NO3 and PO4 yesterday.
NO3 were at 20 ppm
PO4 were at 1,8 ppm at least
So a lot of nutrients in the water column, but I guess that's the point of EI?
For water movement, I have the Dennerle Scaper's Flow, which is an hang on filter that was made for my tank line, it doesn't seem too low...
For organic matter, I siphon the substrate everytime I water change, there is still a bit of dirt, caused by the old parts of the HC.

 

[_Maq_]

Wait, what does the high oxygen consumption do?

Less oxygen for plants.

 

[Fernystein]

Less oxygen for plants.

But plants do not use oxygen to photosynthesize, they use co2

 

[_Maq_]

But plants do not use oxygen to photosynthesize, they use co2

Plants respire oxygen 24/7.

 

[PARAGUAY]

Add more plants a lot more fast growing stems ,Salvinia or floaters of your choice . A few daily water changes

 

[alnitak]

Salve ! Benvenuto

You said that your tank was sort of neglected for some months, you had algae issues, so maybe your plant were "exhausted" by fighting and adapting to a "neglected" environment. Now you tried to adjust things in the right way, but another time they have to adapt again.
I agree with the idea of adding fast growing fresh plants, to balance the environment. Maybe reduce the load of fertilizers by changing water. Let your plants the time to adapt, I'm quite sure they will retrieve soon
Cordiali saluti

 

[Fernystein]

Salve ! Benvenuto

You said that your tank was sort of neglected for some months, you had algae issues, so maybe your plant were "exhausted" by fighting and adapting to a "neglected" environment. Now you tried to adjust things in the right way, but another time they have to adapt again.
I agree with the idea of adding fast growing fresh plants, to balance the environment. Maybe reduce the load of fertilizers by changing water. Let your plants the time to adapt, I'm quite sure they will retrieve soon
Cordiali saluti

Yes it was neglected early in the year, but now it's a few months that I'm regularly fertilizing and changing water, with scarce results 😕, even if everything seems to be there: column fertilization (which is abundant as per EI method), CO2 which has been green for a week straight now, and light seems to be just enough to not get too much gda on the glass and rocks.
Probably I'll have to wait more, since CO2 has been increased only 7 days ago, but the point is: I almost don't see pearling on the plants, even at the end of the photoperiod.

 

[alnitak]

I understand, but the existing plant have to adapt to their new conditions, and it can take months. During this time, the existing leaves seem in bad condition, and they will start growing new leaves adapted to the new conditions. They were used to have poor fertilization, and now it is abundant. The old leaves are not going to start absorbing higher quantities of ferts, they will use the ferts as they were programmed for: for low fert. The new ones yes, they will be born with high ferts and they will grow using high ferts.
Pearling is just related to the saturation of oxygen you have in the water. Not pearling does not mean that the plants are in bad conditions. It ony means that the oxygen they produce is completely dissolved into the water. On the other side, plants in bad condition can pearl, if the water is completely saturated with gases.
Yes, wait quietly, do not change too much things in the same time, add new plants, and enjoy

 

[_Maq_]

the existing leaves seem in bad condition, and they will start growing new leaves adapted to the new conditions. They were used to have poor fertilization, and now it is abundant. The old leaves are not going to start absorbing higher quantities of ferts

Can you complement your theory with something like scientific papers, or so?

 

[alnitak]

Preventing damage, holes and algae on older leaves of aquatic plants

Why do old leaves deteriorate in the first place? The primary reason in planted tanks is that a change in the environment that requires the plant to reprogram its enzymes to make best use of what is available in the current environment. Plants cannot heal broken or disintegrated leaves but will...

www.2hraquarist.com

 

[_Maq_]

@alnitak
Thank you. 2hraquarist is not exactly 'scientific' resource, and many statements are debatable, but one thing is definitely correct: Plants re-combine proteins while responding to change in outer environment. It is estimated that plants re-combine 15 to 25 per cent of their proteins daily.
I'd like to stress again the need of oxygen, because I can sense @Fernystein still somehow does not accept it. Re-combination of proteins means energy consumption. That requires respiration. Respiration requires oxygen. For plants' survival, respiration is more important than CO2 & nutrients. Without respiration, plant even cannot uptake nutrients, because it, too, requires energy.
Take a human for an example - to live, you need food, water & oxygen. If you get deprived of all of them, lack of which of them is going to kill you first?